Nature frequently utilizes opposing factors to create a stable activator gradient to robustly control pattern formation. Specifically, during developmental processes, tight spatial regulation often results from the combined action of stimulatory and inhibitory factors. In such reaction schemes, the reactions of morphogens and their diffusion through a tissue are adequate in describing morphogenesis and creating sharp boundaries in patterns. However, the diffusion/reaction of stimulatory factors alone results in the formation of shallow gradients that make cellular discrimination of spatial cues difficult. Prior to the invention described herein, the art-recognized strategy for delivering stimulatory factors alone to promote regeneration has ignored this fundamental principle of developmental biology. As such, there has been a long-felt need in the art for the discovery of new approaches to locally manipulate regenerative processes via exogenous factor delivery.